yt._config.XSRF_TOKENQUFFLUhqbF9Eb1VRYXNhU3E1ZnJhNkV0RURIRHNKVGRNd3xBQ3Jtc0trYmlWV3BQcXBYYUZnUDV3OHRBYjJQTjZZSGFOTjVXWnVJTEFqTXoyanluR3BtcDdMVl9hRjd6TDBwZzFqTjFXWnJEN012U3JlR2dfVFNlZUNNQ3BfUEN0SjdJX1lLWFRlY1hGOU44SjR6aHd1UGJGcnl3SzVpS3ZNeHJXRkxfdHhEZkljM1BEMFZUVVpCRnFhNFhsN29SdG04RUE=
is clearly a base64 encode of AAE-Hjl_DoUQasaSq5fra6EtEDHDsJTdMw|ACrmsKkbiVWpPqpXaFgP5w8tAb2PN6YHaNN5WZuILAjMz2jynGpmp7LV_aF7zL0pg1jN1WZrD7MvSreGg_TSeeCMCp_PCtJ7I_YKXTecXF9N8J4zhwuPbFrywK5iKvMxrWFL_txDfIc3PD0VTUZBFqa4Xl7oRtm8EA

see the pipeline, it separates between........ ;)

anyway..

yt._config.BG_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
is clearly what you want, it is symmetric encription with very simple (to guess) SALT prefix....

yt._config.BG_IU
looking for the engine?
//www.google.com/js/bg/aXNjA53wkEezSIZZYd1pyMkv-q1HQWFUMg3c80I_Vqs.js

is clearly generated (custom) version of the generic dec-engine, embedded with....

anyway,
nothing (REALLY) interesting here, you can not decipher for yourself....
...